Food insecurity is a major health problem that has pervasive effects on many human biological outcomes. In particular, there are compelling theoretical and empirical reasons to expect that the relationship between food insecurity may be directly related to mental health morbidities, and may be quantifiable in developing country settings. This preliminary study examined whether caretaker reports of food insecurity were associated with anxiety and depression among four ethnic groups in two communities of rural Tanzania. In-home interviews were conducted in June–August of 2005 among female caretakers (n = 449). In addition to collecting household and demographic data, modified versions of the USDA's food security module and Hopkins Symptom Checklist (HSCL) were used to measure food insecurity and anxiety and depression. Consistent with predictions, the results showed a strong positive correlation between a caretaker's score on the food insecurity instrument and her summed response on the HSCL (P < 0.0001). This association was maintained in all four ethnic groups, even when controlling for individual-level covariates such as caretaker's age and marital status. Issues of causality and hypotheses that might explain this robust finding are discussed, as are methodological and theoretical implications. Am. J. Hum. Biol. 18:359–368, 2006. © 2006 Wiley-Liss, Inc.